1. Field of the Invention
The present invention relates to coordinate input apparatuses, coordinate input systems, coordinate input methods, and pointers.
2. Description of the Related Art
A method has been proposed in which, during a presentation with a computer and a large display system, a speaker standing near a screen directly specifies a point on the screen by a pointer or the like to operate the computer or to modify the image being displayed.
As described in Japanese Unexamined Patent Application Publication No. Hei-4-37922, for example, a system is disclosed in which a speaker standing near a screen on which an image is projected specifies a predetermined portion of the displayed image by a pointer having a light emitting unit at a tip, held by the speaker; a TV camera captures the entire image on the screen, including the light emitting unit; an image processing apparatus discriminates the optical image of the light emitting unit from the projected image to take it out as a positional signal; and a computer is controlled or the projected image is modified according to the positional signal.
In the above-described conventional example, the position of the optical image of the light emitting unit on the screen on which the image is projected or in a projected-video optical path is captured by the video camera to obtain its two-dimensional coordinates.
The system becomes complicated, however, because the scanning method of the projected image needs to be related to that of the captured image to discriminate the optical image of the light emitting unit from the projected image. In addition, the luminance of the optical image of the light emitting unit needs to be sufficiently higher than that of the projected image, which is impossible in terms of energy. When the luminance of the optical image is similar to that of the screen, it is difficult to discriminate the optical image of the light emitting unit from the projected image.
A method is also described in which the screen is illuminated by laser light, the entire image of the screen is captured by a video camera, and the laser light is discriminated from the projected image, but this method has the same problem. Especially if the luminance of the image of the laser light is increased, a safety problem occurs and the use of the laser light is not suited to presentations.
For a presentation with a computer and a large display system, just a usual pointer is used conventionally.
The present invention has been made in consideration of the foregoing conditions. Accordingly, it is an object of the present invention to provide a coordinate input apparatus, a coordinate input system, a coordinate input method, and a pointer which allow simple and safe detection of the point specified by the user on a screen for computer manipulation and displayed-image modification.
The foregoing object is achieved in one aspect of the present invention through the provision of a coordinate input apparatus including detecting means for detecting diffuse light; light-collecting means for collecting diffuse light emitted in a projection optical path; and generating means for generating positional information on a projection plane from the light collected by the light-collecting means.
The foregoing object is achieved in another aspect of the present invention through the provision of a coordinate input system including projection means for projecting an image; light emitting means for emitting diffuse light having a predetermined wavelength; detecting means for detecting the diffuse light emitted by the light emitting means; light-collecting means for collecting diffuse light emitted in the projection optical path of the projection means; and generating means for generating positional information on a projection plane from the light collected by the light-collecting means.
The foregoing object is achieved in still another aspect of the present invention through the provision of a coordinate input method including the steps of detecting diffuse light; collecting diffuse light emitted in a projection optical path; and generating positional information on a projection plane from the light collected in the light-collecting step.
The foregoing object is achieved in yet another aspect of the present invention through the provision of a coordinate input method including the steps of projecting an image; emitting diffuse light having a predetermined wavelength; detecting the diffuse light emitted in the light emitting step; collecting diffuse light emitted in a projection optical path; and generating positional information on a projection plane from the light collected in the light-collecting step.
The foregoing object is achieved in a still yet another aspect of the present invention through the provision of a coordinate input apparatus including light emitting means for emitting diffuse light; holding means for holding the light emission state of the diffuse light emitted by the light emitting means; light-emission control means for controlling the light emission of the light emitting means; and a grip. The operation section of the light-emission control means is disposed close to the top of the grip, and the holding means is disposed close to the bottom of the grip.
The foregoing object is achieved in a further aspect of the present invention through the provision of a long pointer including a grip section at a first end of an elongated body; and a light emitting section for emitting diffuse light at a second end of the body. The light emitting section emits the diffuse light in a direction different from the longitudinal direction of the pointer.
The foregoing object is achieved in a still further aspect of the present invention through the provision of a long pointer including a grip section at a first end of an elongated body; and a light emitting section for emitting diffuse light at a second end of the body. The portion disposed between the grip section and the light emitting section expands and contracts.
The foregoing object is achieved in a yet further aspect of the present invention through the provision of a storage medium including a program code for a detecting step of detecting diffuse light; a program code for a light-collecting step of collecting diffuse light emitted in a projection optical path; and a program code for a generating step of generating positional information on a projection plane from the light collected in the light-collecting step.
The foregoing object is achieved in a still yet further aspect of the present invention through the provision of a storage medium including a program code for a projection step of projecting an image; a program code for a light emitting step of emitting diffuse light having a predetermined wavelength; a program code for a detecting step of detecting the diffuse light emitted in the light emitting step; a program code for a light-collecting step of collecting diffuse light emitted in a projection optical path; and a program code for a generating step of generating positional information on a projection plane from the light collected in the light-collecting step.